The objectives of this study are: 1) to evaluate the biodistribution of fluticasone propionate in the oral cavity, trachea, bronchial passages and lungs as a function of time after oral inhalation when administered using the Flovent metered dose inhaler (MDI) formulation with the manufacturer's actuator according to package directions. 2) to estimate the rate of absorption from each region. 3) to compare the observed time-dependent distribution achieved in four different spacer groups: aerochamber, inspirese, volumatic, and no spacer at all.